Texas Instruments new 4-GHz quadrature modulator

Texas Instruments’ TRF370317 is a high-performance IQ modulator that meets the stringent requirements of GSM, CDMA2000, TD-SCDMA, W-CDMA, and WiMAX, as well as emerging next-generation wireless standards such as LTE and multi-carrier GSM. The TRF370317 enables conversion from baseband or intermediate frequency directly to RF frequencies, thereby reducing bill of material (BOM) costs and board space.

“The improved linearity performance of the TRF370317 IQ modulator allows manufacturers to deploy pico, micro or macro basestations, targeting a variety of wireless air interfaces for multi-carrier applications,” said David Briggs, general manager of TI’s RF and digital radio products. “The state-of-the-art linearity performance of the TRF370317 modulator is consistent across a broad frequency range so that it can be used across multiple customer platforms targeting various communications standards. The TRF370317 is an ideal solution for basestation manufacturers looking to reduce the capital and operating expenditures of their service provider customers while meeting all transmission performance requirements.”

Texas Instruments’ TRF370317 has an ultra-low noise floor of −163 dBm/Hz and features an industry-leading output third order intercept point (OIP3) of 26.5 dBm, which significantly improves the adjacent channel power ratio in cellular basestation transmitter designs. The TRF370317 offers up to 4.5 dB better OIP3 than its nearest competitor. The device is capable of accepting input signals that range from zero (DC) to 350 MHz and generating a modulated RF output from 400 MHz up to 4 GHz. This broad range of input and output frequencies offers designers utmost flexibility and support for a wide range of communications standards.

Texas Instruments’ TRF370317 quadrature modulator can easily interface with a variety of digital-to-analog converter (DAC) devices, allowing for flexibility in RF transmitter design. When coupled with TI’s DAC5688, a 16-bit, 800-MSPS dual interpolating DAC, the TRF370317 provides a highly linear, compact solution for multi-carrier implementations. The low-noise DAC5688 further simplifies implementation by integrating phase, gain and DC offset adjustments for performance optimization. RF transmitters designed using this direct launch architecture save space, power, BOM components and cost when compared to superheterodyne transmitter implementations.

Texas Instruments 4-GHz TRF3703 family now includes the TRF370317 as well as previous members, the TRF370315 and the TRF370333. Operating from a single 5-volt supply, the TRF370317 modulator is capable of driving a single-ended 50-ohm load without any external matching components. Output compression of 12 dBm, unadjusted carrier leakage of -40 dBm (at 2 GHz) and unadjusted sideband suppression of -50 dBc (at 2GHz) all serve to keep signal quality high and simplify transmitter design.